The United States said Saturday a tough, year-end deadline for a giant free trade pact in the Asia-Pacific was achievable, after negotiators made \"significant progress\" on sensitive issues. US Trade Representative Michael Froman sounded an upbeat tone following negotiations on the Indonesian island of Bali with his counterparts from the 11 other nations involved in the planned Trans-Pacific Partnership. \"We spent a great deal of time this week working on TPP. The TPP countries are strongly committed to working to conclude negotiations this year,\" Froman told reporters. US President Barack Obama has said he wants to reach a deal by the end of this year on the TPP, which would account for more than 40 percent of the global economy. The United States has spearheaded the negotiations for the free trade area, describing it as creating \"gold standards\" for the 21st Century economy by taking into account fast-changing sectors such as intellectual property.